Medical procedures involving ablation of the heart may be used to cure a variety of cardiac arrhythmia, as well as to manage atrial fibrillation. Such procedures are known in the art. Other medical procedures using ablation of body tissue, such as treating varicose veins, are also known in the art. The ablation energy for these procedures may be in the form of radio-frequency (RF) energy, which is supplied to the tissue via one or more electrodes of a catheter used for the procedures.
The application of the ablation energy to body tissue, if uncontrolled, may lead to an unwanted increase of temperature of the tissue. It is consequently important to control the temperature of the tissue during any medical procedure involving ablation. One method for control is to irrigate the tissue being ablated. However, irrigation requires components to deliver fluid from a proximal end of the catheter to its distal end. With catheter distal ends having diameters on the order of millimeters, space is often a primary constraint on the design and configuration of distal ends that provide for fluid delivery components. Moreover, with distal ends having tip and ring electrodes, such fluid delivery components must define fluid pathways that can provide axial flow and radial flow but occupy minimal space and avoid interfering with other functional aspects of the distal end, such as force sensing.
Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that to the extent any terms are defined in these incorporated documents in a manner that conflicts with the definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.